The present invention relates generally to data communication. More particularly, the present invention relates to a Universal Serial Bus (“USB”) interface for mobile devices.
Expansion modules can increase functionality of certain mobile devices. For instance, an expansion module can be plugged into a personal digital assistant (“PDA”) to provide network connectivity or wireless communications. The expansion module might include a game card.
A typical expansion module is connected to a mobile device via a parallel bus. The bus is proprietary to each device, and it typically has between twenty-four and sixty-four pins. Because the bus is proprietary, the expansion module cannot be readily used with personal computers, PDAs made by different manufacturers, and other computer-based products.